The Blood Service - The Capital Adventures, #1

Aaron's only crime was self-defense. At just thirteen, he was sentenced to life, and shipped off to the outer rim to labor for the Empire until the end of his days. He had made his peace with it, even found a new family. Until one creative colony commander concocted a fresh way for these criminals to be of service to humanity. Conscripts for War, front-line fighters against a vicious alien threat.
They were all expected to die-but Aaron's first contact with the horrifying indigenous creatures would alter the fate of a Galaxy.If you enjoyed Ender's Game or Red Rising, pick up The Blood Service. Join Aaron Havenes and his found family in this first sci-fi action trilogy in Capital-verse!